Top seed and defending champion Sargon Isaac has cruised through his group to book a place in the Round of 16 of this year's United States National Snooker Championship at the Snooker 147 Bar & Grill in Houston, Texas.

The Californian justified his position as title favorite with three straight Group A match victories out of three without the loss of a single frame, but his main rivals were also in very good form in the group stage of the Championship.

Sargon Isaac pictured in action during his first Group A match against Jason Orlando

The number two seeded player and three-times former champion Ahmed Aly Elsayed also advanced into the Round of 16 with three Group D victories, which included a top break of 57, and the number three seed and former champion Ajeya Prabhakar was very impressive as he scored excellent breaks of 55 and 76 on the way to winning Group E without conceding a frame.

Arizona's Romil Azemat was also in very fine form as the number four seed and 2006 Championship runner-up came through Group G with an umblemished frame record, though the number five seed Henry Wong found the going a little more tough in Group H as he claimed the runner-up spot to the home debutant Championship player, Mark White.

A top break of 53 assisted Raymond Fung's easy passage out of Group C as the number six seed from New York hopes to go one better than he did in the 2004 Championship, however the number seven seed, Jian Qiang Wang, was the only seeded player not to qualify as he failed to get out of Group F, yielding the top two places to Texas debutant players Andy Jewtha and Omar Moton respectively.

One of the most impressive performances from the group phase however was from 77-year-old Tom Kollins, as the record five-time Champion seeded eight in the Championship won all four of his Group B matches which included a 2-1 victory over group runner-up, the former U.S. Open 9-Ball Pool Champion Corey Deuel.